False-twist device

ABSTRACT

False-twist device comprising disc-shaped friction units mounted on two parallel rotatable shafts to form cuneate throats in which yarn to be false-twisting may be positioned, and threading means including thread-guides for receiving the yarn and shiftable to position the yarn in the throats.

ilnited States Patent Raschle 1 1 Oct. 2, 1973 1541 FALSE-TWIST DEVICE 2.923.121 2/1960 Tully 57/724 1 2,939,269 6/1960 Dohson... 57/77.4 [75] Inventor: Josef Raschle, Buetschw1l, 302163 2/1962 Findlow I v I H 57/77 4 Swltlerland 3,287,890 11/1966 Mclntosh ct 111.. 57 77.4 Assignccz Heberlein & C0. AG GulL 3,345,811 10/1967 Gilchrist 57/77,4 X

Switzerland [22] Filed: P"- 201 1972 Primary Examiner-Donald E. Watkins [211 App] 245966 AtmrneyJoseph M. Fitzpatrick et a1.

[31)] Foreign Application Priority Data May l4 1971 Switzerland 6945/71 ABSTRACT Feb. 22, 1972 Switzerland 1 2533/72 5 s CL 57 774 False-twist device comprising disc-shaped friction units 5 1 m CL DOlh 7 92 og 1 04 mounted on two parallel rotatable shafts to form cune- 3 i 4 7 77 3 77 45 ate throats in which am to be false-twistin ma be 0- edofSearch 5/ y g y P sitioned, and threading means including thread-guides v for receiving the yarn and shiftable to position the yarn [56] References Cited in the throam UNlTED STATES PATENTS 1030.179 6/1912 Hildcn 57/77.4 8 Claims, 3 Drawing Figures FALSE-TWIST DEVICE The present invention relates to devices treating textile yarns and more particularly, to devices for imparting a false-twist to such yarns through frictional contact with same.

Devices for producing false-twist in textile yarns are known by means of which twist is imparted to the yarn by direct frictional contact with moving surfaces. Thus, for example, a device is known from British Pat. No. 933,438 in which, on each of three parallel shafts, a number of circular discs is provided at a certain distance from each other, the discs being so-arranged on each shaft that they enter into the spaces provided between the discs mounted on the other shafts and the rims of the adjacent discs slightly overlap one another. These discs are provided with a groove on their rims into which a ring of a material with a high coefficient of friction, preferably of rubber-like material, has been inserted and which is in frictional contact with the textile yarn. Such rubber-like materials, however, present the disadvantage that they are subject to rapid wear in use for false-twisting yarns of synthetic material such as polyamides or polyester, for which reason the rings inserted into the rims of the discs have frequently to be renewed.

Thus, I have conceived apparatus of the class described which avoids, or at least substantially reduces, this disadvantage and permits the use of friction discs with low-wear rims and which is particularly suitable for texturing yarns of synthetic thermoplastic material.

In essence, my invention resides in apparatus characterized by a first rotatable shaft on which several friction units are placed at equal distances, each unit consisting of a number of discs, the planes of the flat sides of which are perpendicular with respect to the axis of the shaft and which are also equally spaced from each other, the diameter of the discs in the central part of each friction unit being the largest, whereas the diameters of the remaining discs successively diminish towards both ends of the friction unit; and by a second rotatable shaft on which friction units consisting of a plurality of discs are arranged so that the discs engage in the spaces provided between adjacent discs of the friction units on the first shaft, whereby in the cuneate throats between the discs of the friction units provided on both shafts, the marginal surfaces of the discs form vaulted supports for the textile yam. The single friction units on the two shafts may be placed at such distances that the textile yarn, after having passed over the vaulted surface in one cuneate throat, may be passed to the vaulted surface in the next cuneate throat.

The fact that the yarn may pass over surfaces forming a total contact angle of between 150 and 400 when a plurality of cuneate throats are used, makes it possible to use discs without special friction surfaces consisting of a material with a high coefficient of friction. The friction units may consist of discs formed entirely of a material with high wear-resistance, such as, for example, metallic oxide ceramic material, of an aluminum basic element coated with oxide or also of hard chrome-plated aluminum.

While apparatus as thus far described has been found to be highly satisfactory in actual use, nevertheless, introduction of the yarn is sometimes difficult, or at least time-consuming, even if relatively large spacing is maintained between the friction units. I, therefore, also contribute, as part of my invention, apparatus which permits safe and rapid introduction of the yarn into the cuneate throats.

Accordingly, I provide two additional shafts parallel to the rotatable shafts mentioned before which additional shafts carry thread-guides arranged opposite the spaces provided between the single friction units. The yarn is passed over the thread-guides and the shafts are then rotated to transfer the yarn into the proper position in the cuneate throats of the friction units.

There has thus been outlined rather broadly the more important features of the invention in order that the detailed description thereof that follows may be better understood, and in order that the present contribution to the art may be better appreciated. There are, of course, additional features of the invention that will be described hereinafter and which will form the subject of the claims appended hereto. Those skilled in the art will appreciate that the conception upon which this disclosure is based may readily be utilized as a basis for the designing of other structures for carrying out the several purposes of the invention. It is important, therefore, that the claims be regarded as including such equivalent construction as do not depart from the spirit and scope of the invention.

A specific embodiment of the invention has been chosen for purposes of illustration and description, and is shown in the accompanying drawings, forming a part of the specification, wherein:

FIG. 1 is a front elevational view of the device according to the present invention;

FIG. 2 is a top plan view of the device; and

FIG. 3 is a longitudinal sectional view taken along line A-A of FIG. 1.

Referring now to the drawings, it will be seen that I provide two rotatable shafts l and 2 which can be driven by a suitable drive (not shown). Three friction units are arranged at uniform distances on shaft 1 and consist each of three circular discs 3, 3, 3"; 4, 4', 4"; 5, 5', 5". The discs of each unit are separated by spacers II, 11'; I2, 12'; 13, 13', respectively. The diameters of the central discs 3, 4', 5' of each friction unit are greater than those of the end or terminal discs 3, 1!; n; 1!

The shaft 2 carries three friction units, each of which consists of two discs 6, 6'; 7, 7'; 8, 8'; separated by spacers l4, l5, 16. The diameters of these discs are equal and correspond to the diameter of the discs 3, 4', 5'. Marginal areas of the discs on shaft 2 overlap marginal areas of the discs on shaft 1, the discs 6, 6; 7, 7'; 8, 8' being arranged on shaft 2 so that they extend into the spaces provided between the discs 3 and 3'; 3' and 3"; 4 and 4'; 4' and 4"; S and 5'; and 5' and 5". By appropriate selection of the extent of overlapping of the marginal areas of the discs of shaft 2 with those of the discs of shaft 1, the rim surfaces form, in the cuneate throats 10, 10', between the discs of the two shafts, vaulted supports for the textile yarn, the rims of all discs having been rounded as by grinding.

As can be seen from FIGS. 2 and 3, the textile yarn 9 runs through cuneate throats l0 and 10' because, after having passed over the rims of discs 3, 6, 3', 6', 3" in the cuneate throat 10, it is made to pass over the rims of discs 4, 7, 4', 7, 4" in the cuneate throat 10' and then again, into cuneate throat 10 passing over the rims of discs 5, 8, 5', 8', 5". In this manner, the yarn passes over a total contact angle of It is, of course, also possible to arrange more than three or, optionally, only two friction units on each shaft whereby the contact angle of the yarn with the disc rims is increased or reduced. It is furthermore, possible to use friction units with more than three discs, such as, for example, five discs on shaft 1, and more than two discs, for example four, on shaft 2. In this case, the two terminal discs of each friction unit of shaft 2 must present a smaller diameter than the two central discs to thus adapt their dimensions in the cuneate throats to the diameters of the discs of shaft 1 between which they are so-positioned that the disc rims form vaulted supports for the textile yarn.

Instead of friction bodies consisting of a plurality of discs separated by spacers, grooved friction units may be used, the grooves being arranged so that disc-shaped parts are formed between the same.

I also provide shafts 20, 21 parallel with the shafts 1 and 2 and on which thread-guides 22 and 23 are fixed on the level of the space between the circular discs 4" and 5; and on which thread-guides 24 and 25 are fixed on the level of the space between the circular discs 3" and 4.

To introduce the textile yarn 9 into the false-twist device, the same is first passed over the thread-guides 22, 23, 24, 25 as shown in FIGS. 2 and 3, which may be done easily and rapidly. Thereafter, the two shafts and 21 are turned, as shown in FIG. 2, the threadguides 24 and being swivelled into positions 24' and 25. At the same time, the thread-guides 22 and 23 are also swivelled. All thread-guides have the shape of rods with free endsbent at an obtuse angle so that the yarn 9, after turning of the shafts 20, 21, is guided away from the thread-guides and passes into position 9, as shown in FIG. 3, i.e., over the disc rims in the cuneate throats l0, 10.

The shafts 1 and 2, and their respective friction units, may then be rotated in the direction indicated by the arrows in FIG. 2 which rotation will impart a false-twist to the yarn in the thoats 10, 10' while the yarn is advanced longitudinally in either direction, i.e., upwardly or downwardly.

From the foregoing description, it will be seen that I contribute a false-twist device of the class described by which I am able substantially to reduce wear on the disc rims while employing discs formed entirely of one material and without having to resort to rims ofv special material; and I am able quickly and safely to thread the device.

I believe that the construction and operation of my novel false-twist device will now be understood and that its advantages will be fully appreciated by those persons skilled in the art.

I claim:

I. A false-twist device of the class described comprising, a first rotatable shaft, a plurality of friction units placed at equal distances on said shaft, each unit consisting ofa plurality of discs, the planes of the flat sides of which are perpendicular with respect to the longitudinal axis of said shaft, said discs being equally spaced from each other, the diameters of the discs in the central part of each friction unit being greater than the others whereas, on both sides, the disc diameters diminish successively towards the terminal discs, a second rotatable shaft, friction units on said second shaft each consisting of a plurality of discs arranged so as to extend into the spaces between adjacent discs of the friction units on said first shaft, the rims of the respective discs being so-shaped whereby in the cuneate throats between the discs of the friction bodies of the two shafts, the surfaces of the discs form vaulted supports for the textile yarn.

2. Apparatus according to claim 1, characterized in that the friction units are arranged on the two shafts at such distances that the textile yarn, after having passed over the vaulted surface in one cuneate throat, may be passed over to the vaulted surface in another cuneate throat.

3. Apparatus according to claim 1, characterized in that at least two friction units are arranged on each of the two shafts.

4. Apparatus according to claim 1, characterized in that each of the friction units on the first shaft comprise at least three discs, and each of the friction units on the second shaft comprise at least two discs.

5. Apparatus according to claim 1, characterized in that the discs consist of metallic oxyde ceramic material.

6. Apparatus according to claim 1, characterized in that the discs consist of an aluminum basic element coated with oxyde.

7. A false-twist device of the class described comprising, a first rotatable shaft, a plurality of friction units placed at equal distances on said shaft, each unit consisting of a plurality of discs, the planes of the flat sides of which are perpendicular with respect to the longitudinal axis of said shaft, said discs being equally spaced from each other, the diameters of the discs in the central part of each friction unit being greater than the others whereas, on both sides, the disc diameters diminish successively towards the terminal discs, a second rotatable shaft, friction units on said second shaft each consisting of a plurality of discs arranged so as to extend into the spaces between adjacent discs of the friction units on said first shaft, the rims of the respective discs being so-shaped whereby in the cuneate throats between the discs of the friction bodies of the two shafts, the surfaces of the discs form vaultedsupports for the textile yarn, and means carrying thread-guides on a level with the spaces between respective friction units and operable to shift the yarn from the thread-guides to the cuneate throats between discs.

8. Device according to claim 7, characterized in that the thread-guides are rods, the free ends of which are bent at obtuse angles. 

1. A false-twist device of the class described comprising, a first rotatable shaft, a plurality of friction units placed at equal distances on said shaft, each unit consisting of a plurality of discs, the planes of the flat sides of which are perpendicular with respect to the longitudinal axis of said shaft, said discs being equally spaced from each other, the diameters of the discs in the central part of each friction unit being greater than the others whereas, on both sides, the disc diameters diminish successively towards the terminal discs, a second rotatable shaft, friction units on said second shaft each consisting of a plurality of discs arranged so as to extend into the spaces between adjacent discs of the friction units on said first shaft, the rims of the respective discs being so-shaped whereby in the cuneate throats between the discs of the friction bodies of the two shafts, the surfaces of the discs form vaulted supports for the textile yarn.
 2. Apparatus according to claim 1, characterized in that the friction units are arranged on the two shafts at such distances that the textile yarn, after having passed over the vaulted surface in one cuneate throat, may be passeD over to the vaulted surface in another cuneate throat.
 3. Apparatus according to claim 1, characterized in that at least two friction units are arranged on each of the two shafts.
 4. Apparatus according to claim 1, characterized in that each of the friction units on the first shaft comprise at least three discs, and each of the friction units on the second shaft comprise at least two discs.
 5. Apparatus according to claim 1, characterized in that the discs consist of metallic oxyde ceramic material.
 6. Apparatus according to claim 1, characterized in that the discs consist of an aluminum basic element coated with oxyde.
 7. A false-twist device of the class described comprising, a first rotatable shaft, a plurality of friction units placed at equal distances on said shaft, each unit consisting of a plurality of discs, the planes of the flat sides of which are perpendicular with respect to the longitudinal axis of said shaft, said discs being equally spaced from each other, the diameters of the discs in the central part of each friction unit being greater than the others whereas, on both sides, the disc diameters diminish successively towards the terminal discs, a second rotatable shaft, friction units on said second shaft each consisting of a plurality of discs arranged so as to extend into the spaces between adjacent discs of the friction units on said first shaft, the rims of the respective discs being so-shaped whereby in the cuneate throats between the discs of the friction bodies of the two shafts, the surfaces of the discs form vaulted supports for the textile yarn, and means carrying thread-guides on a level with the spaces between respective friction units and operable to shift the yarn from the thread-guides to the cuneate throats between discs.
 8. Device according to claim 7, characterized in that the thread-guides are rods, the free ends of which are bent at obtuse angles. 